Some microphones, for example, micro-electro-mechanical systems (MEMS) microphones, have an omnidirectional response (that is, they are equally sensitive to sound in all directions). However, in some applications it is desirable to have an unequally sensitive microphone. A remote speaker microphone, as used, for example, in public safety communications, should be more sensitive to the voice of the user than it is to ambient noise. Some remote speaker microphones use beamforming arrays of multiple microphones (for example, a broadside array or an endfire array) to form a directional response (that is, a beam pattern). Adaptive beamforming algorithms may be used to steer the beam pattern toward the desired sounds (for example, speech), while attenuating unwanted sounds (for example, ambient noise).
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.